Arthroscopic surgical repairs of a ruptured anterior cruciate ligament in the knee are known in this art. A rupture of the anterior cruciate ligament (“ACL”) is often seen in sports related injuries. In a typical arthroscopic procedure, the surgeon prepares the patient for surgery by insufflating the patient's knee with sterile saline solution. Several cannulas are inserted into the knee and used as entry portals into the interior of the knee. A conventional arthroscope is inserted through one of the cannulas so that the knee may be viewed by the surgeon remotely. The surgeon then drills a tibial tunnel and a femoral tunnel in accordance with conventional surgical techniques using conventional surgical drills and drill guides. A replacement anterior cruciate ligament graft is then prepared and mounted in the tibial and femoral tunnels, and secured using conventional techniques and known devices in order to complete the knee reconstruction.
Several types of anterior cruciate ligament grafts are available for use by the surgeon in ACL reconstruction. The grafts may be autografts that are harvested from the patient, for example patellar bone-tendon-bone grafts, or hamstring grafts. Or the grafts can be xenografts, allografts, or synthetic polymer grafts. There are various known methods of securing the femoral end of an ACL graft in the femoral tunnel. The methods include cross-pinning, and the use of femoral tunnel interference screws. Of particular interest is a procedure wherein a cross-pin is used to secure the graft in the femoral tunnel. When such a device is used, a transverse tunnel is drilled into the bottom of the femor such that it intersects the femoral tunnel. When using a cross-pinning technique, the surgeon prepares the graft by forming of folding it into a loop. Typically this is preceded by whip stitching the ends of the graft in a conventional manner. After the top end of the graft loop is emplaced in the femoral tunnel, the cross-pin is then inserted into the transverse tunnel and through the opening in the loop of the graft, thereby both securing the graft in place in the femoral tunnel and substantially preventing it from moving in the femoral tunnel.
Although the existing methods of performing ACL reconstruction using cross-pins are satisfactory for their intended purpose, and provide the patient with the desired therapeutic result, there is a constant need in this art for improved methods of performing ACL graft reconstruction using cross-pins. In particular, one critical aspect of a cross-pinning method is the ability to place a graft in a femoral tunnel such that when the cross-pin is inserted through the transverse tunnel it is precisely placed in the opening of the graft loop below the top of the graft loop. It can be appreciated by those skilled in this art that placement of the cross-pin above the top of the graft loop will result in the graft not being adequately secured in the femoral tunnel, with a likelihood of a catastrophic failure. Precise placement of a cross-pin into the opening of a graft loop is presently accomplished in this art by using guide wires and cannulated cross-pins that are inserted over the guide wires. In one known method, a guide wire consisting of a flexible filamentary member is actually looped through the transverse tunnel and down through the femoral and fibial tunnels, such that an end extends out through both sides of the transverse tunnel, and a bottom loop extends out through the bottom of the tibial tunnel. A graft is folded to form a graft loop and placed about the bottom loop of the guide wire such that the guide wire runs through the graft loop opening. The ends of the guide wire extending out through the openings of the transverse tunnel are tensioned to pull the guide wire and graft up through the tibial and femoral tunnels into a desired position for fixation, and a cannulated cross-pin is then threaded over the guide wire and mounted in the transverse tunnel to secure the upper part of the graft loop in the femoral tunnel. Although this method succeeds in emplacing a graft in the femoral tunnel and securing it with a cross-pin, there are some disadvantages associated with its use. For example, it requires that the graft be pulled longitudinally through the tibial and femoral tunnels by pulling transversely on the flexible filamentary member ends that exit the sides of the transverse tunnel. This may result in damage to the bone surrounding the interiors of the femoral and transverse tunnels. In addition, it can be a lengthy and time-consuming process since it is inefficient to move a graft longitudinally through a tunnel by pulling transversely on the flexible filamentary member.
Accordingly, there is a need in this art for improved methods of ACL knee reconstruction using cross-pins.